deteriorate

Etymology

Learned borrowing from Late Latin dēteriorātus, past participle of Late Latin dēteriorō, derivative of Latin dēterior (“worse”).

verb

1. (transitive) To make worse; to make inferior in quality or value; to impair.
   to deteriorate the mind
2. (intransitive) To grow worse; to be impaired in quality; to degenerate.
   During this fine run through Fife the weather had deteriorated rapidly, and as we passed Wormit and came onto the Tay Bridge heavy rain clouds were piled over the sea. 1947 January and February, O. S. Nock, “"The Aberdonian" in Wartime”, in Railway Magazine, page 7
   It was turning into an abysmal afternoon for Newcastle and it deteriorated further when Tiote saw red for his challenge on Jon Ashton. January 8, 2011, Paul Fletcher, “Stevenage 3 - 1 Newcastle”, in BBC